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Matter-Antimatter Bias Seen In Fermilab Collisions
ubermiester writes "The New York Times is reporting that scientists at Fermilab have found evidence of a very small (about 1%) average difference between the amount of matter/antimatter produced in a series of particle collisions. Quoting: '[T]he team, known as the DZero collaboration, found that the fireballs produced pairs of ... muons ... slightly more often than they produced pairs of anti-muons. So the miniature universe inside the accelerator went from being neutral to being about 1 percent more matter than antimatter.' This finding invites theorists to explain why there is so much more matter than antimatter in the universe, when the Standard Model suggests that there should be equal amounts of each." Here is the paper as submitted to Physical Review (PDF). The DZero team is looking forward to getting detailed data from the LHC once it ramps up operationally.
That is a hypothesis used by cosmologists but it isn't part of the Standard Model. The Standard Model predicts particle behavior, not as much the macroscopic stuff. For most purposes the Standard Model agrees with the cosmological observations. This is one example where the Standard Model may be missing something or need tweaking.
The antimatter is very upset at the bias, and is petitioning for full recognition and the payment of reparations.
For some experiments, 1% might be attributable to error. I've never done practical particle physics, though. Does this fall under experimental error, or is stuff like this usually re-creatable to seventeen decimal places?
I may not know much science, but I do know that margin of error is important.
I'm trying to imagine what kind of sample size you'd need to represent, well, everything in the universe.
Sample size and significance calculations are generally done assuming an infinite population from which to sample, so "everything in the universe" is actually as close to perfect agreement between the math and the reality as you can get.
The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
Your expensive tube is doing fat lot of good, eh?! You go Fermilab! LHC can suck it!
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
However, he died in a suicide bombing attack soon after he filed the petition, so the petition no longer matters.
It would be so funny to discover now that the laws of physics are uneven in space...
That the same experiment gets you different results depending on which sid of the Milky Way you are...
Or they could be uneven in time. Maybe every 54.12 years the relation between produced matter/antimatter switches from 1:1.01 to 1.01:1.
I'm probably misunderstanding something here, but it seems that they have discovered that when the big bang happened, then because of this property, a bit more matter was created than anti-matter out of wherever they came in the first place, the rest of it annihilated with each other and everything else is made up from the "extra bits". This seems fairly reasonable.
Now, it is also known that new matter-antimatter element pairs are being created and annihilated all the time everywhere, this is where Hawking radiation comes from.
Does this new discovery mean, that it would be possible, that instead of an antimatter-matter pair a matter-matter pair is created sometimes instead and therefore the amount of matter in the universe is increasing (even if by a tiny amount)? Or are the conditions needed for this to happen too extreme to ever take place outside of big bangs and accelerators? Although as I understand some cosmic rays have far greater energies than accelerators.
Real physicists - please help me make sense of it all!
I am SO cool I can keep meat fresh for a WEEK!!!!
>>The momentum of the Big Bang, the energy we will get back in the eventual collapse...
Eventual collapse?
Haven't kept up with physics, eh? =)
Wasn't this the previously supposed hypothesis? That the big bang held a slight matter bias.
Slashdot has known this for more than a decade. After all, this isn't "news that anti-matters".
Want to improve your Karma? Instead of "Post Anonymously", try the "Post Humously" option.
The Tevatron is so thoroughly outclassed by the LHC that they have to take advantage of every opportunity to make a press release and show that they are still relevant. Once the LHC starts producing science data there will be impossible to justify funding for the Tevatron. The whole of Fermi Lab. (which uses about half the science money given by the D.O.E.) will be in danger of being closed, so they are fighting for survival. During the Bush administration they had to get private funding to avoid lay-offs. http://tierneylab.blogs.nytimes.com/2008/07/02/good-news-or-less-bad-news-for-american-science/
To be fair, Slashdot has known both the affirmation and negation of nearly all propositions.
10 PRINT CHR$(205.5+RND(1)); : GOTO 10
That wasn't a suicide bombing, that was him trying to hug his girlfriend. While both their houses were alike in dignity, it turned out that their physical differences were too much for even love to overcome.
which is totally what she said
What is, "there used to be a lot more matter and antimatter before they started canceling each other out and now we live amongst the debris"?
or, from my safety fifth-grader...
What is "the standard model is wrong"?
And I don't mean that in a bad way. The "flat earth" hypothesis was an _amazing_ deduction at its inception. It was only off by eight inches declination for every mile. This was a _tiny_ margin of error. But error compounds and so does any other form of tiny, so eight inches per mile, an error of ~.0126% (e.g. 8/63360) was enough to make the earth round.
Ta dah! 8-)
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Had you read the abstract, you'd know that Fermilab's result is b+anti-b decay, not p+anti-p, so LHC is fine as long as they can specifically track which muons came from b quark decays.
As a matter of fact, they have a special detector just for that (it's not general-purpose, because b+anti-b pairs decay within centimetres from their creation point, so they actually drop particle tracker 5mm from the beam). See LHCb experiment.
I refuse to use
This is yet another reason why you shouldn't read mainstream media to get your physics news. Just reading the article summary makes me shiver all over.
Please, there are no fireballs at a particle collider and we are many many orders of magnitude in energy away from recreating the conditions after the Big Bang.
There is no miniature universe anywhere. Nothing went from being neutral to more matter than antimatter. Given that the (anti)matter in question here are (anti)muons
that would imply violation of charge conservation, which is not what they observed. This has nothing (well almost nothing, I'll explain in a sec) to do with why there is
so much more matter than antimatter in the universe, and the Standard Model does not suggest that there should be equal amounts either. The only correct
representation of facts in there is that the paper is indeed from the D0 collaboration and it has to do with seeing 1% more muons than antimuons.
Okay, so what did they do? They looked at decays of neutral B-mesons. These are curious mesons, because they oscillate back and forth between being a ..."), in this case direct evidence of new physics beyond the ...
B and an anti-B. If you ever took quantum mechanics: The propagating energy eigenstates are |B> +/ |anti-B> while |B> and |anti-B> are eigenstates of charge-conjugation+parity (CP).
The B can decay into a mu+ (antimuon) + other stuff, the anti-B can decay into a mu- (muon) + other stuff. (In both cases the other stuff has the opposite charge, so total
charge is conserved.) They saw a 1% asymmetry in the amount of mu+ vs. mu- which means that during the oscillation back and forth they end up 1% more often in one
than the other state which means there is a matter-anti-matter asymmetry in their behavior (technically there is CP violation in the mixing). The newsworthy fact is that in
the Standard Model this particular asymmetry (CP violation in mixing) is predicted to be about 25times smaller. With the uncertainties they quote that makes a 3-sigma discrepancy
which is regarded enough to claim "evidence of something" (you need 5 sigma to claim "observation of
Standard Model, which is what particle physicists have eagerly been looking for for the last decades. Personally, I'm holding my breath until I see the same measurement
from CDF (the other experiment at Fermilab). There have been many 3-sigma descrepancies in the past
As far as the universe is concerned, today we only have matter (forget about particle colliders, the point is there are no stars or huge clouds of anti-hydrogen out there).
As the theory goes after the Big Bang there were equal amounts of matter and antimatter, which would eventually have all annihilated into radiation and we wouldn't be here.
The matter we see today is from a tiny, 1 in 10^9, asymmetry in the amount of matter vs. anti-matter that was generated dynamically by particle reactions after the Big Bang.
When the universe cooled down and all the anti-matter got annihialted the tiny excess of matter was left over, which is the matter we see today. To generate this asymmetry one
needs (among other things) CP violation. There is CP violation in the Standard Model, it's just not nearly enough (several orders of magnitude) to generate the required asymmetry in the early
universe. It is totally not straightforward what the 1% asymmetry in the B-anti-B mixing from above translates into in the early universe, although I'm quite sure people are looking at
it right as I speak. I would be very surprised if it was enough though.
Because good theories always make fundamental predictions that need to be contradicted by reality and then tweaked later in an ad-hoc fashion without ever revising their underlying principles. That's great science! Ah well, whatever gets you grants and funding right? In that case, status quo it is! We must always be openly hostile to all competing theories, refuse to publish them so they can be peer-reviewed, etc. That's progress.
In a generic sense it's a quite easy to publish a new, competing theory. That's the kind of thing most encouraged by the current peer review culture, as long as it's self consistent and matches observations.
"I zero-index my hamsters" - Willtor (147206)
You are correct in that.